QSPI flash issue on i.MX8QXP

[giuseppepagano1]

Hi all,

on a custom board I'm currently facing a problem in accessing QSPI flash storage:

I can erase and write the flash memory without problem, but when I read back it for checking data, I have always error on firts byte, and later every 512 byte.  

If I read the flash starting from an offset (different from 0x0), the error is again in first read byte, so I understand that bytes on the flash are alway correctly written, but it is the read operation that file on first and subsequent 512 bytes.

In the screenshot I'm goint to show on the left what I write, andh on the right what che i read.

vimdiff betwwen whta we write, and what we read back

It seems to be a problemi with i.MX8X QSPI controller, or with the clock.

Did anyone else encounter the same issue ?

Regards

Giuseppe

[igorpadykov]

Hi Giuseppe

issue may be related to FlexSPI timings defined by LUT (it is different for different qspi-nor flashes).

Example can be found in sect.18.2.5.3 Application on Serial NOR Flash device (example for Cypress Flash S25FS128S)   i.MX 8DualXPlus/8QuadXPlus Applications Processor Reference Manual

and in M4 SDK_MEK-MIMX8QX,  ..flexspi/octal/polling_transfer/flexspi_octal_polling_transfer.c

customLUT[CUSTOM_LUT_LENGTH] = {..}

SDK is available on https://mcuxpresso.nxp.com/en/welcome

Best regards
igor